This invention relates to flexible light pipes which are coated for improved performance and environmental protection and, more particularly, to improved flexible light pipes having improved light output and which can be bent through relatively sharp angles without distorting the protective coating.
Flexible light pipes are well known and one modification of such pipes is described in U.S. Pat. No. 3,641,332 dated Feb. 8, 1972 to Reick et al. This pipe utilized a polymethyl-methacrylate core with a "Teflon" resin protective overcoat spaced from the core.
Light pipes for decorative applications are described in a brochure originated by Roo International of Australia. Such pipes carry a protective overcoat which tends to cause uneven light patterns, especially when the flexible pipe is bent through relatively small angles. This type of pipe can be used conformed into letters, etc. to provide the effect of a neon sign.
Shrink-fit plastics are well known and are used for a variety of applications, one of which is for the protection of fluorescent lamps as described in U.S. Pat. No. 3,602,759 dated Aug. 31, 1971 to Evans. These shrink-fit lamp overcoatings can also be used as a filter, a light-polarizing component, or an encasement for a reflector.